16 - access("PARENTENTI8_"."IDPARENTENTITY"=41 AND
"PARENTENTI8_"."DEPTH">0)
As a closing remarks, why I really don't understand is that query B is
really fast on a tiny corpus (2 docs), but slower on a bigger corpus
(2000 docs). If exists really stop at the first matching line, it should
be as fast in both cases (assuming a matching line could be found in
almost every document).